Speed up named data map + add uint32 support

[metascroy]

Summary:
his diff significantly speeds up named data map insertion by switching from bytes(tensor.untyped_storage()) to tensor.numpy().tobytes() for converting tensors to bytes. The new _tensor_to_bytes() helper function provides a much faster conversion path, which should noticeably improve XNNPACK and Vulkan lowering times since these backends heavily use the named data store during serialization.

Additionally, this diff adds torch.uint32 to the ScalarType mapping, enabling support for unsigned 32-bit integer tensors in ExecuTorch.

Changes:
_named_data_store.py: Added _tensor_to_bytes() helper that uses numpy().tobytes() for fast tensor-to-bytes conversion, with special handling for bfloat16 (which numpy doesn't support natively)
tensor.py: Added torch.uint32 → ScalarType.UINT32 mapping

Differential Revision: D92447071

[pytorch-bot]

🔗 Helpful Links

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❌ 6 New Failures, 2 Pending, 2 Unrelated Failures

As of commit 4211221 with merge base fdb386c ():

NEW FAILURES - The following jobs have failed:

• pull / test-samsung-models-linux / linux-job (gh)
  RuntimeError: Command docker exec -t b2d10d7a94ca3091577be72f8303d04806cd56cc779f3e53a9b92dd069b65dc9 /exec failed with exit code 1
• pull / test-samsung-quantmodels-linux / linux-job (gh)
  RuntimeError: Command docker exec -t 76a0b15792c2104284a713b068554a0659faf56402115e2279e1789a8de75e9b /exec failed with exit code 1
• pull / unittest / linux / linux-job (gh)
  RuntimeError: Command docker exec -t 6ddbe581d47aca86ceb6b0a8fed4d4832725ba5007f8e05af69e763a612b8263 /exec failed with exit code 1
• pull / unittest-editable / linux / linux-job (gh)
  RuntimeError: Command docker exec -t cd372ed494114c81ab78dfc5c82759f1e4650f7fe2739e014c94431fa056358e /exec failed with exit code 1
• pull / unittest-editable / macos / macos-job (gh)
  export/tests/test_target_recipes.py::TestTargetRecipes::test_linear_model
• trunk / unittest-release / linux / linux-job (gh)
  RuntimeError: Command docker exec -t 84587692a2ef84767ff14fce7125db8daa98c0bc7e7bf1ec2b734cd02ebe599d /exec failed with exit code 1

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / unittest / macos / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / unittest-release / macos / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1

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[meta-codesync]

@metascroy has exported this pull request. If you are a Meta employee, you can view the originating Diff in D92447071.

[github-actions]

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[GregoryComer]

Nice find.